should a new PCV valve completely seal on boost?

[VanIsleDSM]

I have my valve cover off, doing a bunch of crap.. so I got a new PCV valvle, the local parts place had a fram brand valve.. I took it home and blew on either side.. air goes out easily as it should, and when blowing on the other side it does block most of the flow.. but if I blow hard a lot goes through.. now I know from blowing on the nylon hose of a boost gauge that I can only boost about 4-5psi with my lungs.. that thing is gonna leak a lot of air at 14psi.. I know it'll be a little better once it's oiled, but still.. is this normal for a new valve, do they not completely seal? I know the best option is to use a nice check valve from mcmaster-carr or something but I'm not at the stage yet, what's a good brand of pcv that doesn't leak when new?

 

[brute]

Even from the dealer, PCV's can leak out of the box. When you buy one, while you're still in the store, just take it out, and do the blowing test like you did. If one side does not leak at all (not even a little bit), and the other side flows, then you should be fine. I run a check valve and haven't looked back since.

 

[steve]

If you can blow from the hose bard side the PCV is trash but even if you can't you need to test then at boost pressure. Most people can't create that sort of pressure with their mouth.

The PCV needs to seal against any leakage under the max boost pressure your will be running. I've yet to find an aftermarket part that worked. Remember that 99% of these PCV valves are for use in non-boosted applications so sealing isn't high on the requirements.

Steve

 

[VanIsleDSM]

thanks guys, I'll be taking it back then.

 

[HustlerTalon]

can you just put a barb nipple fitting on the valve cover where the PCV goes (like the one on the intake manifold)???